Arsenic accumulation, distribution and source analysis of rice in a typical growing area in north China.

Rice (Oryza sativa) is believed to be a major source of arsenic (As) exposure in humans, especially in Asia. In this study, As accumulation, distribution and source analysis of rice are investigated in five sites (SZ, QH, XZ, WS and JX) in the Nansi Lake area, an important rice-growing region in north China. Findings show that total As average concentrations were 6.3-13.6 mg kg and 5.5-9.9 μg L in paddy soil and irrigation water, respectively. Inorganic arsenic As(III) and dimethylarsinic acid DMAs(V) were the major speciation in polished rice, with a small proportion of As(V) evident. Notably, the percentage of As(III) increased by 63.9-68.5%. Based on survey data, the addition of total As to farm soil due to fertilizer application was 31.5-11,580 mg per hectare per year. According to the results of Spearman's rank correlation analysis and Principal Component Analysis (PCA), As levels in soil and irrigation water may be important factors influencing As concentration in rice.